This analysis was based on a review of the DiSC website and responses to specific questions posed to the publisher.
The RMP makes it clear that it aims to measure an individual's motivations - what Professor Steven Reiss calls basic desires or psychological needs. According to the theory of 16 basic desires, our motivations determine our values, influence the development of our personality traits and predict our behavior.
DiSC measures behavior patterns. It does not measure motivation.
The RMP was developed scientifically. Professor Reiss did not use predetermined ideas when developing the RMP. That is, he did not start with universal goals that motivated everyone. Instead, he developed the RMP with an empirical (scientific) approach. He created a 328-item questionnaire on what might motivate people and then used factor analysis to interpret the results. Three exploratory factor studies and one confirmatory factor study, each with a different sample, revealed that 128 items could be grouped into specific scales. In short, Professor Reiss allowed the data to determine motivations.
The DiSC is based on William Marston's belief that behavioral expressions of emotions can be categorized into four main types. Walter V. Clarke developed a Self-Definition assessment based on Marston's behavioral model, and then John Geier created the DiSC using information from Self-Definition and clinical interviews. In response to a direct question to the publisher: "DiSC has no history of using an empirical approach."
The RMP measures the test-taker's motivation intensity on each of the 16 scales from weak to strong. While previous motivation theorists spoke of motivation and personality in general terms, Professor Reiss was the first to develop a conceptual platform linking motivations to specific personality traits. According to Professor Reiss, motivation intensity is central to understanding the development of personality traits. Everyone is motivated by the same 16 goals, but what makes us individuals is how badly we want each of these goals. In short, RMP allows personality traits to be assessed on a continuous variable, which is the method of choice for researchers.
DiSC categorizes the test taker into one of four different types. These types are based on Marston's ideas about behavioral differences between people and are not supported by scientific data that these four types exist to explain individuality. Individual differences - whether personality traits like sociability or physical traits like height - are better represented by a continuum rather than a category.
Has the Test been Independently Validated? Test authors and publishers provide data to demonstrate the reliability and validity of their assessments. This applies to both RMP and DiSC. However, only the RMP has been validated by independent researchers. There are published studies conducted in Canada (Professor Thomas Mengel of the University of New Brunswick), Finland (Professor Päivi Mayor and Marjaana Herlevi of Tampere University of Applied Sciences), Poland (Professor Agata Chudzicka-Czupala and Agata Basek of SWPS University of Social Sciences and Humanities), and the United States (Professor Kenneth R. Olson of Fort Hays University).
In response to a direct question, the publisher of the DiSC stated: "Although we offer evaluations to researchers interested in independent DiSC research, we have not had any researchers submit validity/reliability results for publication in academic journals."
The RMP was developed by Professor Steven Reiss to increase knowledge about human nature, not for commercial reasons. Professor Reiss was educated at Dartmouth College, Yale University and Harvard University. In addition to the RMP, he developed the Anxiety Sensitivity Index, which has been translated into more than 20 languages and is widely used in the assessment of anxiety disorders. His work in the field of developmental disabilities was recognized with five national awards and he gave invited talks in more than ten countries. Professor Reiss's obituary was published in American Psychologist, an honor given only to a very small number of psychologists who have made significant advances in the field.
William Marston studied at Harvard University and wrote a popular psychology book that introduced the idea of categorizing people into one of four types. Marston is also known as the creator of the female superhero Wonder Woman. Walter V. Clarke was an industrial psychologist who worked in Human Resources and tried to develop a tool for personnel selection. John Geier studied speech at Northwestern College and then earned a PhD in communication theory at the University of Minnesota. He founded a company to market the Personal Profile System® (PPS), which later became DiSC.
As a result, RMP is the clear choice for clients looking for a scientifically developed and independently validated measure of what motivates people.